A white supremacist woman accused of killing four people during a violent road trip across the Pacific Northwest with her boyfriend pleaded guilty on Tuesday to racketeering in a deal that could send her to prison for life, federal prosecutors said.

The racketeering charge to which Holly Ann Grigsby pleaded guilty encapsulates all the crimes alleged in the case, said Gerri Badden, spokeswoman for the Portland-based U.S. Attorney's Office. Grigsby, in her late 20s, is due to be sentenced in June.

The couple were arrested in 2011 in northern California after what authorities described as a bloody, two-week crime spree that began in the Puget Sound city of Everett, Wash., with the slayings of boyfriend David Joseph Pedersen's father and step-mother.

The three-state road trip, during which the duo are accused of killing a middle-aged black man and a 19-year-old stranger singled out because they thought he was Jewish, ended with Grigsby allegedly telling police she and Pederson were on their way to "kill more Jews" in Sacramento, Calif.

The couple's white supremacist associations were also evident from tattoos on Pedersen's neck and through racist Facebook postings by Grigsby.

Federal prosecutors said in court papers filed in February they would not seek the death penalty against Grigsby or Pedersen, who is serving a life sentence in Washington state on separate charges stemming from the killing spree.

Pederson pleaded guilty in 2012 to Washington state counts of first-degree murder for the shooting death of his father, David "Red" Pedersen, 56, and the stabbing death of his stepmother, Leslie Mae "DeeDee" Pedersen, 69, in Everett.

He is scheduled to go on trial in July in Portland on federal racketeering and other charges linked to the case, Badden said.

The 24-page federal indictment says Pedersen researched the names and addresses of Jewish organizations in Seattle, Portland and Sacramento to identify "potential targets for elimination" and that he had a "draft 'press release' to alert the media about the purpose of the planned murders."

The indictment describes their purpose as "promoting and advancing a white supremacist movement to 'purify' and 'preserve' the white race and 'reclaim our country.'"

Although the indictment says Pedersen and Grigsby were members of a criminal organization, no other individuals were named or referred to in the document.